It has been disclosed that certain polyesters may be formed which exhibit melt anisotropy. See, for instance, (a) Polyester X7G-A Self Reinforced Thermoplastic, by W. J. Jackson, Jr., H. F. Kuhfuss, and T. F. Gray, Jr. 30th Anniversary Technical Conference, 1975 Reinforced Plastics Composites Institute, The Society of the Plastics Industry, Inc., Section 17-D, Pages 1-4, (b) Belgian Pat. Nos. 838,935 and 828,936, (c) Dutch Pat. No. 7505551, (d) West German Nos. 2520819, 2520820, 2722120, 2834535, 2834536 and 2834537, (e) Japanese Nos. 43-223; 2132-116; 3017-692; and 3021-293; (f) U.S. Pat. Nos. 3,991,013; 3,991,014; 4,057,597; 4,066,620; 4,067,852; 4,075,262; 4,083,829; 4,093,595; 4,118,372; 4,130,545; 4,130,702; 4,146,702; 4,153,779; 4,156,070; 4,159,365; 4,161,470; 4,169,933; 4,181,792; 4,183,895; 4,184,996; 4,188,476; 4,201,856; 4,219,461; 4,224,433; 4,226,970; 4,230,817; 4,232,143; 4,232,144; 4,238,598; 4,238,599; 4,238,600; 4,242,496; 4,245,082; 4,245,084; 4,247,514; 4,256,624; 4,265,802; 4,267,304; 4,269,965; and 4,272,625; (g) U.K. Application No. 2,002,404; and (h) European Patent Applications 0008855, 0018145. See also commonly assigned U.S. Ser. Nos. 109,575, filed Jan. 4, 1980 (now U.S. Pat. No. 4,285,852); 128,l759, filed Mar. 10, 1980 (now U.S. Pat. No. 4,299,756); 128,778, filed Mar. 10, 1980 (now U.S. Pat. No. 4,318,841); 169,014, filed July 15, 1980; and 194,196, filed Oct. 6, 1980 (now U.S. Pat. No. 4,279,803); and 194,199, filed Oct. 6, 1980 (now U.S. Pat. No. 4,318,842).
Commonly assigned U.S. Pat. No. 4,161,470 discloses a polyester consisting essentially of 6-oxy-2-naphthoyl and 4-oxybenzoyl moieties.
Commonly assigned U.S. Pat. No. 4,219,461 discloses a polyester consisting essentially of 6-oxy-2-naphthoyl, 4-oxybenzoyl, dioxyaryl and dicarboxyaryl moieties.
U.S. Pat. No. 4,118,372 broadly discloses polyesters which consist essentially of recurring units derived from diacids, diols, and hydroxy acids. The inclusion of a 1,4-dicarboxycyclohexane moiety is disclosed, for example, at column 2, line 5, and in several of the Examples. Furthermore, R.sub.1, R.sub.2, and R.sub.3 in the formulas of U.S. Pat. No. 4,118,372 may be, as defined in Columns 1 and 2, "radicals selected from the group of (1) single and fused 6-membered aromatic carbocyclic ring systems wherein the chain extending bonds of the ring system if attached to the same ring are positioned 1,4- to each other, and if attached to different rings, are in positions parallel and oppositely directed, . . . " Two-ring systems are illustrated at Column 2. See also U.S. Pat. No. 3,991,013 which contemplates a polyester which may include a moiety derived from hexahydroterephthalic acid.
In our commonly assigned United States Ser. No. 194,199, filed Oct. 6, 1980 (now U.S. Pat. No. 4,318,842), is disclosed a polyester derived from 6-hydroxy-2-naphthoic acid, aromatic diol, 1,4-cyclohexanedicarboxylic acid, and optionally an aromatic diacid. See also the poly(ester-amide) of commonly assigned U.S. Ser. No. 214,557, filed Dec. 9, 1980.
It is an object of the present invention to provide an improved melt processable polyester capable of forming an anisotropic melt phase at a temperature below approximately 350.degree. C., and preferably below approximately 320.degree. C.
It is an object of the present invention to provide an improved polyester which forms a highly tractable melt phase which is capable of readily undergoing melt processing.
It is an object of the present invention to provide an improved polyester which forms an anisotropic melt phase at a temperature well below its decomposition temperature.
It is a further object of the present invention to provide an improved polyester which is capable of undergoing melt processing to form quality molded articles possessing unusually high impact properties.
These and other objects, as well as the scope, nature, and utilization of the present invention, will be apparent to those skilled in the art from the following detailed description.